Abraham Sofaer was a Burmese-born British actor who played the Thasian who reclaims Charlie Evans in Charlie X and voiced the Melkotian in Spectre of the Gun.
Abraham Sofaer (1896–1988) had a long career on the London and New York stage and in British and American films, where his resonant voice was much in demand.
In Charlie X he appears as the Thasian, the shimmering face that materialises on the Enterprise bridge to take Charlie Evans back. He explains that his people gave the boy his powers so that he could survive, and that Charlie can never live safely among humans.
Sofaer returned in the third season to supply the voice of the Melkotian in Spectre of the Gun, pronouncing sentence on Kirk's party for trespass and, at the end, inviting the Federation to make contact.